When Google suspects that a site has been hacked they will indicate this in their search results with a message that says “This site may be hacked”. Sites are very commonly hacked, and you may be a target even though you might not suspect it.  A huge number of sites are hacked each day across the web in order to gain illicit information regarding its users or to damage the reputation of a site.

Hackers will often add additional pages to sites that are vulnerable in order to redirect site visitors to harmful or otherwise undesirable destinations. A common ploy is to redirect visitors to bogus ecommerce sites.

After determining that your site has been hacked you must identify and resolve the issue as fast as you can. You must ensure the security of your site in order to protect your visitors from illicit content and safeguard the integrity of your site.

Here are some actions you can take to detect content that has been hacked onto your site:

• Look for suspicious directories or URLs

Periodically perform a Google site search. This will look something like the following: [site:mysite.com.au].  If there are any directories or ULRs that come up that you don’t recognise, you have probably been hacked.

It’s also helpful to set up Google Alerts for your website. For instance, you may create an alert such as [site:mysite.com.au{sex|gambling|casinos|erectile dysfunction)].  You will then receive an alert if any of these words are found on your website.

• Look In Google Webmaster Tools for unusual search queries 

Look in the search queries page on GWT. It will show search queries that display URLs on your site.  If you detect some unanticipated queries, it is an indicator that your site has been hacked.  These queries may be in a language other than the language used on your site, so be on the lookout for them.

• Enable GWT’s Email Forwarding 

If Google believes that your site has been hacked, they will send a message to you. These messages will show up in GWT’s Message Centre. However, it’s also a good idea to have these messages forwarded to your email address.

Ways To Prevent And Fix Hacking 

• Remain Informed

GWT’s security issues will display site pages that they believe have been hacked. It will also give you quite a bit of information to assist you in rectifying the problem. Read this documentation thoroughly in order to quickly resolve these issues.

• Protecting Your Site From Hackers

Clearly, the best scenario is to prevent hacking in the first place rather than having to repair a hacked site. Quite often, hackers will exploit security breaches on frequently used site management software. Here are some prevention tips:

• Always run that latest available version of your software
• Sign up for any security announcements that are provided
• If this software is managed by your host, make sure you use a trusted hosting provider 

This should help you to detect and repair your site if it has been hacked and to prevent hacking in the first place.  You should report suspicious sites to Google using their spam reporting tool.